--- ray/src/util/rttree_reduce.c	2011/06/03 18:12:58	2.4
+++ ray/src/util/rttree_reduce.c	2013/10/03 03:36:11	2.8
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rttree_reduce.c,v 2.4 2011/06/03 18:12:58 greg Exp $";
+static const char RCSid[] = "$Id: rttree_reduce.c,v 2.8 2013/10/03 03:36:11 greg Exp $";
 #endif
 /*
  *  A utility called by genBSDF.pl to reduce tensor tree samples and output
@@ -152,7 +152,7 @@ print_tree(const TNODE *tp, const int bmin[], int l2s)
 		for (i = 0; i < 1<<ttrank; i++) {
 			float	val;
 			for (j = ttrank; j--; )
-				bkmin[j] = bmin[j] + (i>>j & 1);
+				bkmin[j] = bmin[j] + (i>>(ttrank-1-j) & 1);
 			val = (ttrank == 3) ? dval3(bkmin[0],bkmin[1],bkmin[2])
 				: dval4(bkmin[0],bkmin[1],bkmin[2],bkmin[3]);
 			printf(" %.4e", val);
@@ -262,7 +262,7 @@ load_data()
 		int	ix, ox;
 		for (ix = 0; ix < 1<<(log2g-1); ix++)
 			for (ox = 0; ox < 1<<log2g; ox++)
-				(*readf)(datarr+((((ix)<<log2g)+(ox))<<log2g),
+				(*readf)(datarr+(((ix<<log2g)+ox)<<log2g),
 						1<<log2g);
 	} else /* ttrank == 4 */ {
 		int	ix, iy, ox;
@@ -270,7 +270,7 @@ load_data()
 		    for (iy = 0; iy < 1<<log2g; iy++)
 			for (ox = 0; ox < 1<<log2g; ox++)
 				(*readf)(datarr +
-				((((((ix)<<log2g)+(iy))<<log2g)+(ox))<<log2g),
+				(((((ix<<log2g)+iy)<<log2g)+ox)<<log2g),
 						1<<log2g);
 	}
 	(*readf)(NULL, 0);	/* releases any buffers */
@@ -291,17 +291,50 @@ load_data()
 		error(WARNING, "binary data past end of expected input");
 }
 
+/* Enforce reciprocity by averaging data values */
+static void
+do_reciprocity()
+{
+	const int	siz = 1<<log2g;
+	float		*v1p, *v2p;
+
+	if (ttrank == 3) {
+		int	ix, ox, oy;
+		for (ix = 0; ix < siz>>1; ix++)
+		    for (ox = 0; ox < siz; ox++)
+		        for (oy = 0; oy < siz>>1; oy++) {
+				v1p = &dval3(ix,ox,oy);
+				v2p = &dval3(ix,ox,siz-1-oy);
+				*v1p = *v2p = .5f*( *v1p + *v2p );
+			}
+	} else /* ttrank == 4 */ {
+		int	ix, iy, ox, oy;
+		for (ix = 1; ix < siz; ix++)
+		    for (iy = 1; iy < siz; iy++)
+			for (ox = 0; ox < ix; ox++)
+			    for (oy = 0; oy < iy; oy++) {
+				v1p = &dval4(siz-1-ix,siz-1-iy,ox,oy);
+				v2p = &dval4(siz-1-ox,siz-1-oy,ix,iy);
+				*v1p = *v2p = .5f*( *v1p + *v2p );
+			    }
+	}
+}
+
 /* Load BSDF array, coalesce uniform regions and format as tensor tree */
 int
 main(int argc, char *argv[])
 {
 	int	doheader = 1;
+	int	recipavg = 0;
 	int	bmin[4];
 	TNODE	gtree;
 	int	i;
 					/* get options and parameters */
 	for (i = 1; i < argc && argv[i][0] == '-'; i++)
 		switch (argv[i][1]) {
+		case 'a':
+			recipavg = !recipavg;
+			break;
 		case 'h':
 			doheader = !doheader;
 			break;
@@ -338,6 +371,8 @@ main(int argc, char *argv[])
 	if (infmt != 'a')
 		SET_FILE_BINARY(stdin);
 	load_data();
+	if (recipavg)
+		do_reciprocity();
 	if (doheader) {
 		for (i = 0; i < argc; i++) {
 			fputs(argv[i], stdout);
@@ -359,7 +394,7 @@ main(int argc, char *argv[])
 	*/
 	return(0);
 userr:
-	fprintf(stderr, "Usage: %s [-h][-f{a|f|d}][-r {3|4}][-g log2grid][-t trim%%] [input]\n",
+	fprintf(stderr, "Usage: %s [-h][-a][-f{a|f|d}][-r {3|4}][-g log2grid][-t trim%%] [input]\n",
 			argv[0]);
 	return(1);
 }